A touch screen, the most simple, convenient and natural means for man-machine interaction, is widely employed in information search, industrial control, self-service, multi-media teaching, electronic games, and so on. Among all the touch screens, a capacitive touch screen plays an important role due to its accuracy, wearability, and longevity, and has a better application prospect. Generally, a capacitive screen includes a touch panel and a display device, both of which being connected via adhesive components (such as adhesive tapes or adhesive agents) on the periphery, with the touch panel providing touch and control functionality, while the display device providing display functionality. The periphery (edges) region for connecting the touch panel and the display device is a black matrix region (i.e., a non-visible region) of the capacitive screen, wherein the periphery (edges) region of the touch panel is a non-active region.
A touch screen may be single faceted or double faceted, with the latter only being the subject of the present disclosure. A touch panel based on mutual capacitance concept of the prior art is shown in FIG. 1, there are multiple rows of sequentially arranged drive lines, e.g., the drive line 20, on a surface (the front surface of FIG. 1, orientated towards the outside of the drawing sheet) of a substrate of the touch panel 1, and there are multiple columns of sense lines, e.g., the sense line 10, on the other surface (the back surface of FIG. 1, orientated towards the inside of the drawing sheet, with components on the back surface delineated with dashed lines). The multiple drive lines extend along the horizontal direction depicted in FIG. 1, on the front surface of the substrate of the touch panel 1, from the left edge of the front surface to the right edge of the front surface. The ends of the multiple drive lines are electrically connected to a drive chip (not shown) at the left edge of the front surface, while the other ends of the multiple drive lines at the right edge of the front surface left floating. The multiple sense lines extend along the vertical direction depicted in FIG. 1, on the back surface of the substrate of the touch panel 1, from the lower edge of the surface to the upper edge of the back surface. The ends of the multiple sense lines are electrically connected to a sense chip (not shown) at the lower edge of the back surface, while the other ends of the multiple sense lines at the upper edge of the back surface left floating. Thus, the drive lines and the sense lines on the two sides of the substrate intersect virtually to form a lattice structure. In actual usage, the drive chip sends a drive signal SD to the drive lines, for example by sending the drive signal SD to the drive lines in a sequentially scanning manner from top to bottom; while the sense chip receives one or more sense signals SS from the sense lines, for example by detecting the sense lines to receive one or more sense signals output therefrom. Hence, by analyzing the drive signal SD and the sense signal SS, it is easy to determine whether the surface of the touch panel is touched, as well as the position of the touch together with the related action, thereby obtaining the manipulation information inputted by the user via the touch panel.
With development of touch screen technology, users demand for larger screen and higher touch control precision, which poses a challenge to prior art techniques. A touch screen with larger size requires longer drive/sense lines, while higher touch control precision requires finer drive/sense lines, which results in bigger resistance of the drive/sense lines and difficulty in detection of the sense signal SS.
In face of the above problem, the inventors provide a solution in the Chinese patent “A capacitive touch screen with fewer peripheral circuits,” with the application number 201711157482.1. As shown in FIG. 2, drive lines on a front surface of a substrate of a touch panel 1 are divided into two groups, with those of the first group disposed on the left half of the surface, e.g., the drive line 21, while those of the second group disposed on the right half of the surface, e.g., the drive line 22. Each corresponding drive line in the two groups aligns with one another along the horizontal direction depicted in FIG. 2, and a gap 30 is formed between the first group and the second group. Wherein, an end of each drive line of the first group is connected to a drive chip at the left edge of the surface, while the other end (at the central axial line of the surface) of each drive line left floating. An end of each drive line of the second group is connected to the drive chip at the right edge of the surface, while the other end (at the central axial line of the surface) of each drive line left floating. Multiple sense lines are arranged on the back surface of the substrate similar to those in FIG. 1, e.g. sense lines 11 and 12. In actual usage, the drive chip sends a drive signal SD to the drive lines in the first and second groups, for example in a sequentially scanning manner from top to bottom, by sending the drive signal SD simultaneously to the drive lines 21 and 22 and subsequently to the two drive lines beneath the drive lines 21 and 22 respectively. The sense chip receives one or more sense signals SS from the sense lines, for example by detecting the sense lines simultaneously. Thus, it can be seen that in comparison with the prior art described in FIG. 1, the drive lines in FIG. 2 are shorter, resulting in decreased resistance. Therefore, even if the solution is applied in a larger size touch screen, or the width of the drive lines is decreased, detection precision for the sense signal SS would not be impacted by the increased resistance.
However, for the aligned pair of drive lines (for example the drive lines 21 and 22) as described in the technical solution of FIG. 2, mutual signal interferences inevitably exist at opposing ends of the aligned pair, which impacts on detection precision for the sense signal SS.
Therefore, a person skilled in the art endeavors to develop a capacitive touch panel, to solve the aforementioned technical problem.